In the end, it will all depend on who wins lot of delegates during the primaries to help in final nomination -or- improve chance of electoral votes.
JFK picked LBJ whom he despised.
Reagan picked Bush-41 who had described Reagan as Voodoo Economist.
Politics can and will make strange bed fellows.
The principles of JFK and LBJ were fluid.
Pretty certain that’s not the case with Cruz.
Trump will never be #2 on anyone’s ticket.